Hi! I make Baby Charmer Slings, they are not adjustable, but I use one with my 18 month old and we are very happy!! You can view my website, www.babycharmerslings.com and look at my measuring directions. Measure your existing sling after you get your measurment and see if it matches. If it does, you might just need a different type. If it is too big or too little by even 1 inch, it is not the correct size. I love my un-adjustable pouch, we get so many uses out of it even now!
I hope this info helps you..... Have a great New Year!!
God Bless,
Holly